After more than a week of tense, sleep-deprived negotiations, delegates at the third UN Climate Change Conference adopted the Kyoto Protocol, committing industrialized nations to cut greenhouse gas emissions by an average of about 5 percent below 1990 levels by 2012. It marked the first time countries agreed to legally binding limits on carbon emissions, though the United States, the largest emitter at the time, later declined to ratify it.
The talks nearly collapsed multiple times before Argentine diplomat Raúl Estrada-Oyuela, chairing the conference, gaveled through a final compromise text in the small hours, well past the deadline. Japan's decision to host the conference in its ancient imperial capital gave the resulting treaty its name and a certain symbolic weight, an old city lending its name to a new kind of global commitment.
The protocol divided the world into developed nations, which took on binding targets, and developing nations, including China and India, which faced none, a split that would fuel years of subsequent argument. The United States signed but never submitted the treaty for Senate ratification, and in 2001 the incoming Bush administration formally rejected it, citing economic concerns and the exemption of major developing economies.
Despite its limitations and the defection of its largest potential emitter, Kyoto established the basic architecture, binding national targets, emissions trading, monitoring, that later climate agreements, including the 2015 Paris Agreement, would build upon and revise. It entered into force in 2005 once enough countries, led by Russia's ratification, pushed it over the required threshold.
Key people: Raúl Estrada-Oyuela